A liquid crystal display device regulates the transmissivity of light by controlling the liquid crystal so as to display an image. The thickness of a liquid crystal layer in a liquid crystal display device is a only few μm, so that the liquid crystal display device has a light weight, a thin thickness and a small size in comparison with a cathode ray tube (CRT) display device.
The liquid crystal display device includes a liquid crystal display panel assembly, a backlight assembly and a chassis.
The liquid crystal display panel assembly uses the liquid crystal so as to display images. Electric fields applied to the liquid crystal by a minute area of the liquid crystal display panel assembly, regulate the transmissivity of the light, so that each of the minute area of liquid crystal display panel assembly have different light quantity respectively. Therefore, the liquid crystal display panel assembly displays images.
The backlight assembly supplies light to the liquid crystal display panel assembly. The back light assembly includes a light guide plate (LGP). The light guide plate converts a linear light from a light source to planar light having uniform luminance. Therefore, the liquid crystal display device displays high quality images. The back light assembly includes a receiving container.
The receiving container receives the back light assembly and the liquid crystal display panel assembly.
The chassis fixes the back light assembly and the liquid crystal display panel assembly. The liquid crystal display panel assembly is fragile. Therefore, the chassis protects the liquid crystal display panel assembly.
The performance of the liquid crystal display device having these elements is determined by the thickness, the weight, the luminance of the display and so on. Especially, when the liquid crystal display device is portable, the thickness, the weight and the volume become more important.
In order to reduce the thickness, weight and volume, many attempts, for example replacing the glass of the liquid crystal panel with the glass having low density, adapting the back light assembly having no sheet, etc. have been tried.
The light guide plate contributes much portion of the weight of the liquid crystal display device. However, replacing the material of the light guide plate may not reduce the weight of the light guide plate.
Further, the thickness of the light guide plate is not easily reduced, due to the arrangement of a lamp.
The thickness of the light guide plate relates to the diameter of the lamp.
A general liquid crystal display device has at least two lamps arranged parallel on a light exiting face of the light guide plate to enhance the luminance.
Therefore, in order to reduce the thickness of the light guide plate, the diameter of the lamp may be reduced. However, there is a limit to reduce the diameter of the lamp.
If the diameter is reduced below the limit, the luminance becomes lower, so that the lamp is useless.